CBDC interoperability challenges—particularly in hybrid setups like the Société Générale–Forge/Banque de France (BdF) 2024 repo pilot and ongoing Les Gardiennes/UBS collaborations—stem from bridging public Ethereum (permissionless, for tokenized collateral like bonds or uMINT funds) with proprietary/permissioned CBDC ledgers (e.g., BdF’s DL3S on Hyperledger Fabric). These pilots use mechanisms like Hashed Timelock Contracts (HTLCs), APIs, and…
